The present invention relates to the field of magnetic resonance imaging (MRI) equipment, and more particularly to a video system including a display for displaying MRI images and patient vital sign data within a magnet room.
MRI is a relatively new scanning procedure being used in the medical community to assist doctors in various diagnostic and other procedures. The scanning procedure requires that a patient lie still inside a tunnel shaped enclosure called the bore. The MRI device uses a strong magnetic field that is generated around the patient's body. Disturbances in the field due to the presence of the body can be detected and translated into images displayed on a viewing screen.
The MRI device includes a large magnet that induces a strong, uniform, and static magnetic field. Generally, the magnetic field ranges from 0.5 Telsa to 2.0 Telsa inside the bore. Gradient coils disposed around the bore induce spatially variant magnetic fields (i.e. gradients) that modify the existing uniform magnetic field. To induce nuclear resonance, a transmitter emits radio waves through a coil, which couples the radio wave energy with the resonating nuclei inside the magnetic field. A receiver, also connected to the coil, receives the disrupted electromagnetic waves. The waves are filtered, amplified, and processed into visual data for viewing by an MRI techologist attending to the procedure. More detailed information regarding MRI equipment is available in a book entitled Nuclear Magnetic Resonance, pp. 53-66 (1st ed. 1981), the contents of which are incorporated by reference.
Typically, the MRI magnet is set up in a magnet room. The patient typically is supine on a table which fits into the magnet bore. In an adjacent room, typically known as the control room, shielded from the magnet room by a penetration panel, an MRI technologist controls the operation of the MRI equipment by a control console. The MRI image processor is set up in an adjacent computer room.
One procedure for which MRI equipment is now being used is non-invasive surgery, typically using a laser fiber device to burn tissue or cancer tumors while at the same time using the MRI device to provide images of the patient to view the effect of the laser operation on the tissue or tumor. A disadvantage is that the doctor conducting the procedure cannot view the MRI images of the patient while inside the MRI magnet room. The reason is that it is nearly impossible for a typical television, video cassette recorder or the like to operate properly in the presence of the strong magnetic fields in the magnet room, and the MRI equipment is very sensitive to high frequency RF leakage from cathode ray tube and other electronic equipment. Therefore, presently the surgeon performing the surgery has to localize the area of interest outside the magnet room using ultrasound equipment. This procedure can be very time consuming because the patient must be moved in and out of the magnet room each time the ultrasound equipment must be used. During the actual surgery when the MRI imagery is being generated, the surgeon must leave the magnet room and go to the operator console area located outside the magnet room to view the MRI images through the operator console monitor. This is also not conducive to good practice and can lengthen the operation.
For similar reasons, a conventional CRT type display for the patient's vital signs or EKG monitoring cannot be used within the MRI magnet room.
Therefore, a need presently exists for a display system permitting MRI images to be displayed to a surgeon or other medical personnel working within the MRI magnet room.